scholarly journals Robustness in glycosylation systems: effect of modified monosaccharides, acceptor decoys and azido sugars on cellular nucleotide-sugar levels and pattern of N-linked glycosylation

2020 ◽  
Vol 16 (4) ◽  
pp. 377-386
Author(s):  
Virginia del Solar ◽  
Rohitesh Gupta ◽  
Yusen Zhou ◽  
Gabrielle Pawlowski ◽  
Khushi L. Matta ◽  
...  
Keyword(s):  
Nucleotide Sugar ◽  
Sugar Levels ◽  
Chemical Perturbation

Chemical perturbation studies reveal robustness in glycosylation systems, based on comparison of LC-MS/MS quantification of cellular nucleotide-sugar levels with the observed N-linked glycan patterns.

scholarly journals Examining the distribution and impact of single nucleotide polymorphisms in the capsular locus of Streptococcus pneumoniae serotype 19A

2021 ◽  
Author(s):  
D.W. Arends ◽  
W.R. Miellet ◽  
J.D. Langereis ◽  
T.H.A. Ederveen ◽  
C.E. van der Gaast - de Jongh ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Nucleotide Sugar ◽  
Single Nucleotide ◽  
Multiple Alleles ◽  
Enzymatic Function ◽  
Significant Difference ◽  
Sugar Levels ◽  
The Impact

Streptococcus pneumoniae serotype 19A prevalence has increased after implementation of PCV7 and PCV10 vaccines. In this study, we have provided, with high accuracy, the genetic diversity of the 19A serotype in a cohort of Dutch invasive pneumococcal disease patients and asymptomatic carriers obtained in the period 2004-2016. Whole genomes of the 338 pneumococcal isolates in this cohort were sequenced and their capsule ( cps ) loci compared to examine the diversity and determine the impact on the production of CPS sugar precursors and CPS shedding. We discovered 79 types with a unique CPS locus sequence. Most variation was observed in the rmlB and rmlD genes of the TDP-Rha synthesis pathway, and in the wzg gene, of unknown function. Interestingly, gene variation in the cps locus was conserved in multiple alleles. Using RmlB and RmlD protein models, we predict that enzymatic function is not affected by the single nucleotide polymorphisms as identified. To determine if RmlB and RmlD function was affected, we analyzed nucleotide sugar levels using UHPLC-MS. CPS precursors differed between 19A cps locus subtypes, including TDP-Rha, but no clear correlation was observed. Also, a significant difference in multiple nucleotide sugar levels was observed between phylogenetically branched groups. Because of indications of a role for Wzg in capsule shedding, we analyzed if this was affected. No clear indication of a direct role in shedding was found. We thus describe genotypic variety in rmlB , rmlD and wzg in serotype 19A the Netherlands, for which we have not discovered an associated phenotype.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

Sites of Insulin Action Using Ferritin Labeling

1971 ◽  
Vol 29 ◽  
pp. 540-541
Author(s):  
Burton B. Silver ◽  
Ronald S. Nelson
Keyword(s):  
Electron Microscopy ◽  
Binding Sites ◽  
Anterior Pituitary ◽  
Insulin Action ◽  
Diabetic Rats ◽  
Insulin Antibody ◽  
Fat Pad ◽  
Target Organs ◽  
Uranium Salts ◽  
Sugar Levels

Some investigators feel that insulin does not enter cells but exerts its influence in some manner on the cell surface. Ferritin labeling of insulin and insulin antibody was used to determine if binding sites of insulin to specific target organs could be seen with electron microscopy.Alloxanized rats were considered diabetic if blood sugar levels were in excess of 300 mg %. Test reagents included ferritin, ferritin labeled insulin, and ferritin labeled insulin antibody. Target organs examined were were diaphragm, kidney, gastrocnemius, fat pad, liver and anterior pituitary. Reagents were administered through the left common carotid. Survival time was at least one hour in test animals. Tissue incubation studies were also done in normal as well as diabetic rats. Specimens were fixed in gluteraldehyde and osmium followed by staining with lead and uranium salts. Some tissues were not stained.

Plasminogen Activation in Diabetes Mellitus: Normalization of Blood Sugar Levels Improves Impaired Enzyme Kinetics In Vitro

1985 ◽  
Vol 54 (02) ◽  
pp. 413-414 ◽  
Author(s):  
Margarethe Geiger ◽  
Bernd R Binder
Keyword(s):  
Plasminogen Activator ◽  
Blood Sugar ◽  
Metabolic Disorders ◽  
Normal Values ◽  
Diabetic Patients ◽  
Type I ◽  
Plasminogen Activation ◽  
Lag Period ◽  
Sugar Levels

SummaryWe have demonstrated previously that fibrin enhanced plasmin formation by the vascular plasminogen activator was significantly impaired, when components isolated from the plasma of three uncontrolled diabetic patients (type I) were used to study plasminogen activation in vitro. In the present study it can be demonstrated that functional properties of the vascular plasminogen activators as well as of the plasminogens from the same three diabetic patients are significantly improved after normalization of blood sugar levels and improvement of HbAlc values. Most pronounced the Km of diabetic vascular plasminogen activator in the presence of fibrin returned to normal values, and for diabetic plasminogen the prolonged lag period until maximal plasmin formation occurred was shortened to almost control values. From these data we conclude that the observed abnormalities of in vitro fibrinolysis are not primarily associated with the diabetic disease, but might be secondary to metabolic disorders caused by diabetes.

Effects of Rapid Infusion of Ethanol on some Factors Controlling Blood Sugar Levels in Man

1972 ◽  
Vol 33 (3) ◽  
pp. 722-733 ◽  
Author(s):  
John W. Dundee ◽  
Martin Isaac ◽  
Elizabeth A. Davis ◽  
Brian Sheridan
Keyword(s):  
Blood Sugar ◽  
Rapid Infusion ◽  
Sugar Levels

744 PB 076 IDENTIFICATION OF BOTH ACID AND NEUTRAL INVERTASE ACTIVITY IN DEVELOPING STRAWBERRY FRUIT

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 539f-539
Author(s):  
Kirk W. Pomper ◽  
Patrick J. Breen
Keyword(s):  
Extraction Procedure ◽  
Invertase Activity ◽  
Assimilate Transport ◽  
Strawberry Fruit ◽  
Fruit Extracts ◽  
Neutral Invertase ◽  
Optimum Ph ◽  
Cold Acetone ◽  
Ripe Stage ◽  
Sugar Levels

Invertase (INV) may influence sugar levels and assimilate transport in strawberry fruit. Several groups, including our own, have only detected acid INV (optimum pH 4.6) in strawberry fruit, however, recently Hubbard et al. (Physiol. Plant. 82:191-196, 1991) reported the presence of a neutral INV (pH 7.5). Since dissimilar isolation protocols may have contributed to the different findings, we re-examined our work with developing `Brighton' strawberry using the extraction procedure of Hubbard et al. Neutral INV activity per gFW (pH 7.5-8.0) increased many fold as fruit developed from green to the red ripe stage. Acid INV activity decreased markedly from green-white to the red stage. In addition, when fruit extracts were precipitated with cold acetone, a pellet contained 60% of the acid INV activity, and a surface coagulation of protein contained 60% of the neutral INV activity. This allowed easy separation of these two enzymes. Extraction methodologies affect isolation of neutral INV activity from strawberry fruit.

Citrus Carbohydrate Levels were Related to Irrigation Frequency but Not Arbuscular Mycorrhizal Fungal (AMF) Inoculum

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498a-498
Author(s):  
Matthew W. Fidelibus ◽  
Chris A. Martin
Keyword(s):  
Soil Water ◽  
Arbuscular Mycorrhizal ◽  
Irrigation Frequency ◽  
Soil Water Tension ◽  
Root Starch ◽  
Carbohydrate Levels ◽  
Amf Communities ◽  
Sugar Levels ◽  
Shoot Mass ◽  
Water Tension

Sugar and starch concentrations in leaves and roots of Citrus volkameriana Tan and Pasq were measured in response to irrigation frequency and AMF inoculum. Non-mycorrhizal seedlings were treated with a soil inoculum from one of five different communities of AMF; two AMF communities from Arizona citrus orchard soils, and three communities from undisturbed desert soils. Plants were assigned to frequent (soil water tension > –0.01 MPa) or infrequent (soil water tension > –0.06 MPa) irrigation cycles and were container-grown in a glasshouse for 4 months before tissues were analyzed. Fungal inoculum source did not affect shoot or root carbohydrate levels. Plants grown under high irrigation frequency had increased leaf and root starch levels and increased root sugar levels compared with those under low irrigation frequencies. High irrigation frequency also increased shoot mass.

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